Filtration

Various filtration methods from Veolia Water Technologies South Africa are
used for the physical, mechanical and biological separation of solids from
treated water. Filtration takes place after the clarification stage as an additional treatment step to remove
any remaining suspended particles and unsettled floc to ensure safe water.

Sand Filtration: Pressure
filters can be used with varying media from sand and activated carbon, to
multiple media layers.

RO is a filtration method used to separate molecules and ions from water
and is generally used to produce potable, ultrapure and process water. High
quality reverse osmosis membranes are manufactured by Veolia specifically for
this type of filtration, and they can be used in Veolia’s package plants for potable water treatment and wastewater treatment.

Filtration Media & Systems

Veolia
Standard Filtration Products

Berkal™ disc filtration systems

For removing contaminants like
fibres, grit sand and algae, these filtration systems achieve high flow rates
of 10 to 120 m3 an hour. Berkal disc filters are compact with high
retention capacities and are available in filtration grades of 20, 50, 100,
0130, 200 and 400 microns.

Some of the benefits are:

Automatic backwashing of individual filters
based on time or pressure differential

A flexible modular design with high scalability

High contaminant removal rates

Air assisted backwashing

Corrosion-resistant pipework

Low running costs and minimal maintenance

Berkofin™ filters

Designed to help prevent wear
and corrosion of downstream pipe work, components and connected equipment, these
filters achieve flow rates of 4.3 to 100 m3 an hour. Ideal for
industrial and domestic applications.

A mechanical, self-cleaning
filter with a large filter area in a small footprint. Solids are caught on the
inside of the filter panels mounted on the two sides of the disc segment. This
impedes the water flow through the disc causing their inner water levels to
rise, which triggers a level sensor which actuates the disc rotation and a
backwash cycle begins. The backwash requires only 0.05 to 3% of the total
filtered water flow.

The Discfilter series consists
of 5 Hydrotech products:

2600 Series: The Hydrotech HSF2600 offers
you up to 230 m2 of filtration area.

2200 Series: The plastic disc design on this
series provides considerably lower weight and 50% more filter area per
footprint compared to the Hydrotech stainless steel Discfilters.

1700, 2100 & 3100: A full range of
microscreen filters with flow capacity up to 1 000 l/s (3 600 m3/h) per filter
and filter opening range of 10-100 microns.

IDRASCREEN™

IDRASCREEN™ represents the range
of high capacity self-cleaning screen filters for wastewaters pre-treatment. They
are equipped with an inner washing system with low/medium pressure to do
periodical cleaning in order to avoid clogging, reducing cleaning, maintenance
and high costs.

A few of the advantages are:

Low investment and installation costs and
low operating costs

High capacity with reduced dimensions

Low power costs and zero additional water
required

More efficient separated solids draining
than traditional filters

Lower costs for screen removal and recycling

Veolia’s
available filters and their configurations

AF-Belt™ Twin Wire Press

Aquaflow’s AF-Belt™ Twin Wire Press is specifically
designed for pulp and paper mill sludge dewatering applications and
applications where sludge inlet consistency and quality vary, as well as for
sludge mixtures with significant bio-sludge content.

AF-Press™

Especially designed for Pulp and Paper sludges,
the size and geometry are chosen on the basis of sludge properties. It is
possible to handle sludges from 5 BDt/d up to 140 BDt/d with one line thanks to
a wide size range and tailor-made process design.

Dusenflo™ filter

The
Dusenflo™ gravity filter is a proven efficient and reliable filtration system
which offers a unique, economical and highly effective potable water filtration
system that provides consistent high-quality, crystal clear potable water.

Eliminator™ Cartridge Filters

Eliminator™
Cartridge Filters are designed to reduce particulate matter from water, either
as part of a water purification system or as a stand-alone filtration unit.
They produce up to 22 m3/hr of filtered water for a wide variety of
process water and general manufacturing applications.

Filtra-Matic™

Used to remove particles larger than 0.5 microns from
streams with up to 150 mg/l of solids, this robust filtration technology from
Veolia uses fixed leaves featuring a central drainage element and a fine outer
mesh of wire cloth. This design, when combined with a filter medium such as
diatomaceous earth, produces high-quality effluents that often need no further
treatment. Filtra-Matic™ can be configured in either a retracting tank shell or
retracting bundle designs for easy maintenance and leaf replacement.

FILTRAFLO™ PACK

FILTRAFLO™ PACK constitutes a complete range of
modular and flexible skid-mounted media pressure filters for municipal and
industrial applications such as drinking water treatment, process water production
and treated water reuse. The municipal product range makes use of Multilayer
Filtration technologies and the industrial range uses FILTRAFLO™ Industrial
Range. Flow rates for the former are from
10 to 100 mᶟ/h per unit and for the latter from 1 to 90 mᶟ/h per unit.

FILTRAFLO™ PACK (Mono/Duo/Trio) pressure sand filters

These are pressure sand filters that reduce turbidity
from water for drinking water treatment, cooling water, pre-filtration for RO
systems, filtering surface water, wastewater treatment and reuse and recycling.
The skid-mounted units are ready to connect and combine to treat different flows
and loads. These units produce from 25 to 100 m3/h per unit, have
fully-automated operation via remote control and are easy to integrate into an existing
plant.

Filtraflo™ filters

Filtraflo™ filters are multiple function filters
incorporating physical, biological and chemical functions as well as
physical-chemical functions. They employ the same basic principle that involves
a rapid gravitational filtration of raw water through a granular media, and the
filtering bed is composed of single or dual media layers.

Filtraflo™ Carb

A Veolia
Water Technologies patent, Filtraflo™ Carb combines physical filtration of
suspended solids with adsorption of organic matter into one treatment using
micrograin activated carbon. It is a chemical free polishing solution involving
micrograin activated carbon that allows the removal of natural organic matter,
the pesticides, and a large spectre of micro-pollutants by adsorption in
treated water while filtering it.

Filtraflo™ filters use the same principle that involves
rapid gravitational filtration of raw water through granular media.

HRD™ systems

Designed
for effective removal of oil and suspended solids from seawater, cooling water
and oil field brine, HRD™ distribution systems control velocity and
hydraulic balance, protecting the media during high flow rates of up to 285 litres per minute per square meter of filter area. The systems are pre-engineered to comply with stringent
specifications and are delivered assembled in a packaged skid, mounted with
piping, valves and controls. HRD™ can combine multiple media options such as
silica sand, garnet and anthracite coal for achieving unparalleled filtration
efficiency that produces effluent quality with solids content below 1 mg/l in a
wide spectrum of low-solids applications. HRD™ is also ideal for treating industrial water
streams in the mining, refining and petrochemical sectors – and sewage
effluents after tertiary treatment where conventional sand filters are not
effective.

Hydrotech Microscreen filters

Hydrotech Drumfilters and Discfilters are cost-effective,
have low energy consumption and an automatic control to optimise capacity.
They’re available in 500 different variations and can, therefore, be used in
applications like industry, municipality, aquaculture, swimming pools and
aquariums.

Hydrotech Beltfilter

Made for efficient filtration and draining of sludge
and wastewater, the Hydrotech Beltfilter is is an automatic, self-cleaning filter
specially designed to achieve optimal performance in systems where high solids
content in dewatered sludge is essential.

Hydrotech Drumfilter

A
mechanical and self-cleaning filter that operates in 3 simple steps, the
Hydrotech Drumfilter is specially designed for high performance in systems
where it is essential to prevent particles from fragmentation.

Idrapress™

Designed
for the conveyance and dewatering of various types of wastewater screenings,
Indrapress™ is capable of drastically reducing the screenings weight and
volume, and consequently the transport and disposal costs.

PowerClean® filters

PowerClean® filters, with superior design and long
filtration runs, are among the most advanced nutshell filtration technologies
available, removing 98% of all suspended solids and insoluble hydrocarbon
particles above 5 microns. They are simple,
automatic systems designed to eliminate filter plugging problems without the
use of air or gas for particulate removal. This is achieved through a quick media
cleaning cycle that generates minimal volumes of backwash wastewater.